Title text:
They’re up there with coral islands, lightning, and caterpillars turning into butterflies.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3135/
There are places in the solar system where the tide rips new mountains up every go around.
Io.
Where is that? Is that on one of the moons of Jupiter?
Io is the most volcanically active place in the solar system, by a long shot.
I remember never believing my parents when they explained it to me as a kid. Clouds being caused by cigarette smoke was reasonable but the moon pulling out the ocean seemed too outrageous.
Been trying to learn about the tides around here so I can tell what I’m seeing on the water. Imagine my joy when I found a Casio, which I collect, with tide and moon phase indicators!
And that’s when I learned the Gulf Coast is strange, has diurnal tides (twice a day) the watch can’t predict. Took me an hour and a half to figure out it would never function. The moon phase works!
the Gulf Coast is strange, has diurnal tides (twice a day)
Diurnal tides are once a day (semidiurnal is twice a day). By the Gulf Coast, I guess you must mean the Gulf of Mexico. I’m living on the other side of the world in the other diurnal region, so I assume our tides are synchronised!
Gulf of America, you extreme left Antifa socialist!!1!one
No idea how I got that backwards. I even looked it up before posting!
Tides go in, tides go out, you can’t explain that.
Casio can’t!
FlatEarthersSayWhat
Thats just the tilting from where the elephants shrug
Everyone was taught the tides look like two giant water bulges going around the earth in line with the moon.
That representation is oversimplified and false.
This is how the tides look like at a global level. It’s messed up.
Ok, that clarifies things so much better for me. Thank you.
You understand it more after that?
I’m more confused, honestly. But that’s hardly surprising.
The pictures they used to teach us the tides as children came to make less sense to me in regards to certain places having higher tides than others. I couldn’t picture how. That animation clarified how tides are ordered by the Moon and made chaotic by the shapes of land. The planetary ocean bulges they taught us as kids stuck with me too long and prevented deeper understanding. It finally clicked for me.
Fair enough.
I just have a hard time translating what what shown in the video to what’s actually happening. Might be a bit too much to take in at once.
Then again, I haven’t cared much about the tides ever, and I only know that the tides are a function of the moon because of Bill Nye, I think.
My HS “education” was pretty bad, honestly.
Look at one spot and see how it repeats. Like the tides between South America and Africa kind of rotates through the Atlantic.
And when Mercury is in retrograde, you can make an excuse for anything being kind of shitty or off.
There better not be mercury in my Gatorade!
No, no, no; We’re just giving Mercury a retro-grade.
I’m thinking maybe a C to C+ at best. I mean it’s kinda ‘retro’, but that’s definitely not the first description that comes to mind.
Y’see, that’s not quite how it works.
Imagine being out exploring new islands, not realizing its low tide. You setup camp for the night on an island that’s relatively flat and close to current sea-level. Then while you’re sleeping the tide comes in and washes your whole camp out to sea…
Come to the beach here in Bordeaux (well, on the coast) and see tourists set up their stuff at low ebb but forgetting they have to watch out for the flood.
There’s an island near me that has a pedestrian causeway at low tide. There are huge signs warning to check tide times or get cut off, but still people don’t get it.
Arcachon?
Cramond Island, Edinburgh
Arcachon?
Cap Ferret but arcachon with the Pilat Dune works too!
if you are exploring islands you probably have a solid idea of how tides work.
You probably should, but that doesn’t mean you do. It’s not like anyone makes you take a quiz to go wander around outside.
Plenty of people get themselves into trouble all the time exploring places/things they know nothing about.
It’s not like anyone makes you take a quiz to go wander around outside.
I knew it! I am so not answering any more of his questions, next time I go out.
WHAT! is your favourite colour?
Blue.
Edit: No! PINK!
…aaaahhhhhh!!!
people like you are why i love lemmy
i lived near the beach for a while and, uh, i have seen tourists do the stupid. i posit they count.
Nah, that’s just Poseidon having a bad mood today. Just have to sacrifice your first child to make it stop for 10 years.
I wonder if anyone has ever done the math on how much (in L or kg) water is moved by the moon each day. It’s got to be something absurd.
Just wanted to mention I see your pfp on every post.
Thank you for keeping lemmy alive and making like 4% of the total posts. Seeing you post brightens up my day.
No homo.
Let’s hope Lemmy grows big enough that I can just be part of the crowd.
I have to assume it’s about one moon’s worth, divided by the distance squared.
That would be its total pull, not just the water.
We probably can estimate the amount of water that’s at a different level from what a moonless Earth would.
We could also say that technically all water is moved somewhat, because gravity is like that.
I think lightning would be crazy to anyone who never experienced a planet with it. Like, “WTF, sometimes your sky does what?”
“Their moon is tidally locked” is an absolutely metal thing to say about a planet.
Tides in the Bay of Fundy, Canada are 16 metres (50 feet).
See, that’s the part that confuses the hell outta me. How can water be higher in one spot than others just due to the Moon’s gravity? Yeah it’s the geography of the area, got it. But still, how?
In the Bay of Fundy, Canada we have the highest tides in the world (53 feet high). It’s enough to make some of the tributary rivers flow backward with the rising tide. I’ve seen it my whole life but it still amazes me to see a harbour completely empty of water with boats sitting on the bottom waiting for the tide to come back in.
woah XKCD is still making comics?
